A number of techniques are available for delivering a therapeutic agent such as siRNA into a cell, including the use of viral transfection systems and non-viral transfection systems. Non-viral transfection systems can include, for example, polymers, lipids, liposomes, micelles, dendrimers, and nanomaterials. Examples of polymers that have previously been studied for cell transfection include cationic polymers such as poly(L-lysine) (PLL), polyethyleneimine (PEI), chitosan, and poly(2-dimethylamino)ethyl methacrylate (pDMAEMA).
Each type of system has its respective advantages and drawbacks. For example, viral systems can yield high transfection efficiency, but may not be as safe as some non-viral systems. In addition, viral systems can be complicated and/or expensive to prepare. Non-viral transfection systems, such as cationic polymers, have been reported to transfer plasmid DNA into cells. However, some drawbacks to the use of cationic polymers include their toxicity to cells and/or their lack of stability.
As such, there is a pressing need for new compounds, compositions, and methods of using cationic components to improve delivery of therapeutic drugs, including nucleic acids, to cells, tissues and organisms.